This is a really cool and original concept, taking pieces from other games and combining them or splitting them makes sense and feels playful. It's a bit hard to get used to at first, like any game with intricate mechanics are, but once I'm looking at how to split up my dominoes or cards, it gives the player a good puzzle.
I really like this, and can see this being a really chunky and interesting mechanic in a full fledged game. Very nice work.